1. Field of the Invention
The present invention relates to a perpendicular magnetic recording (i.e. write) head provided with a magnetic pole and a side shield, and a magnetic recording device mounted with the same.
2. Description of the Related Art
In recent years, with an improvement in an areal recording density of a magnetic recording medium (hereinafter, referred to as “recording medium”) typified by a hard disk, desired is a performance improvement in a magnetic recording head. In response to such a trend, as a recording method of the magnetic head, in substitution for a longitudinal magnetic recording method in which the direction of a signal magnetic field is set to the in-plane direction of the recording medium, attention is attracted to a perpendicular magnetic recording method in which the direction of the signal magnetic field is set to the direction intersecting a plane of the recording medium. The reason why is that there are such advantages that a linear recording density improves, and a recording medium on which information has been already recorded is less susceptible to thermal fluctuation.
A magnetic recording head of the perpendicular magnetic recording method (hereinafter, referred to as “perpendicular magnetic recording head”) is provided with a thin-film coil for generating magnetic flux and a main magnetic-pole layer which leads the magnetic flux generated in the thin-film coil to a recording medium. This main magnetic-pole layer includes a tip portion (magnetic pole) having a fine width, the tip portion generating a magnetic field for recording (recording magnetic field).
In order to handle a high recording density while suppressing a spread of the perpendicular magnetic field, regarding a configuration of the perpendicular magnetic recording head, it is considered to provide a side shield on both sides of a magnetic pole with a gap in between in a write-track width direction (for example, see Japanese Unexamined Patent Publication Nos. 2004-326990, 2004-022004, and 2005-310363).
Under such circumstances, the areal recording density of a recording medium recently tends to increase more and more, so that it is highly desired to more optimize the configuration of the perpendicular magnetic recording head. However, the conventional perpendicular magnetic recording head, provided with the side shield, has a trade-off relationship between ensuring the magnitude of the perpendicular magnetic field and suppressing the spread of the perpendicular magnetic field, and it is difficult to realize both ensuring the magnitude of the perpendicular magnetic field and suppressing the spread of the perpendicular magnetic field, so that there is still room for improvement in recording performance.
These lead to a strong desire for realizing both ensuring the magnitude in the recording magnetic field and suppressing the spread of the recording magnetic field, thereby improving the recording performance.